Circulating lymphocyte subsets in obsessive compulsive disorder, major depression and normal controls

Background: Obsessive compulsive disorder (OCD) shares several features wit h depressive illness (e.g., comorbidity, early escape from dexamethasone su ppression, effectiveness of serotonergic pharmacotherapy). It was of intere st to establish whether OCD, like major depression, was also associated wit h immune alterations, notably elevations of circulating natural killer (NK) cells. Method: Circulating lymphocytes were determined from morning blood samples taken from OCD and major depressive patients, as well as from age- and sex-matched controls. Stress perception and coping styles were evaluate d in order to assess whether such variables accompanied the NK alterations. Finally, in a subset of patients, symptoms of the illness, stress/coping, and circulating lymphocytes, were also evaluated following 12 weeks of anti depressant medication (serotonergic reuptake inhibitor). Results: The major depressive and OCD patients reported increased perception of day-to-day st resses, coupled with reliance on emotion focused coping styles. Moreover, c irculating NK cells were elevated among male OCD and major depressive patie nts, whereas only a modest increase of NK cells was seen in female major de pressives. Twelve weeks of medication alleviated depressive and OCD symptom s, and resulted in normalization of NK cells in the major depressives, Howe ver, in OCD patients the reduction of symptoms was not accompanied by signi ficant variations of circulating NK cells. Conclusions: Although major depr ession and OCD are both accompanied by elevated circulating NK cells, at le ast in males, normalization of NK cells following treatment was only eviden t in depression. The persistent elevations of NK cells among male OCD patie nts may reflect either a trait characteristic of the illness, or symptom re duction and not true remission. Limitations: Although elevations of lymphoc yte subsets in major depressive and OCD patients were observed, conclusions concerning immune status in OCD ought to be held in abeyance pending asses sment of other indices of immune and cytokine functioning. (C) 1999 Elsevie r Science B.V. All rights reserved.